The integrity and function of the periodontium can beÂ compromised by traumatic injuries or periodontitis. Currently availableÂ clinical therapies are able to stop the progression of periodontitis and allow the healing of periodontal tissue. However, an optimal strategy capable of restoring the anatomy and functionality of the lost periodontalÂ tissue is still to be achieved. Herein is proposed the development of anÂ injectable hydrogel system able to release a growth factors and cells to theÂ periodontal defect. This injectable system is based on a photo-crossÂ linkable hydrogel, prepared from methacrylated hyaluronic acid (me-HA)Â and incorporating platelet lysate (PL). The delivery of growth factors andÂ cells in situ is expected to enhance regeneration of the periodontium.Â Various formulations of me-HA containing increasing PL concentrationsÂ were studied for achieving the formation of stable photo-cross-linkableÂ hydrogels. The produced hydrogels were subsequently characterized toÂ assess mechanical properties, degradation, protein/growth factor release profile, antimicrobial activity and response towardÂ human Periodontal Ligament fibroblasts (hPDLFs). The results demonstrated that it was possible to obtain stable photo-crosslinkable hydrogels incorporating different amounts of PL that can be released in a sustained manner. Furthermore, theÂ incorporation of PL improved (p < 0.02) the viscoelastic properties of the hydrogels and enhanced their resilience to theÂ degradation by hyaluronidase (HAase). Additionally, the PL was shown to provide antimicrobial properties. Finally, hPDLFs,Â either seeded or encapsulated into the developed hydrogels, showed enhanced proliferation over time (p < 0.05), proportionallyÂ to the increasing amounts of PL present in the hydrogel formulations.

por

dc.description.sponsorship

The research leading to these results has received funding from Fundacao para a Ciencia e a Tecnologia (FCT) under project BIBS (PTDC/CVT/102972/2008) and project ACROSS (PTDC/BBB-BIO/0827/2012), from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number REGPOT-CT2012-316331-PO-LARIS and from the project "Novel smart and biomimetic materials for innovative regenerative medicine approaches" RL1-ABMR-NORTE-01-0124-FEDER-000016 cofinanced by North Portugal Regional Operational Programme (ON.2-O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF).